North Korean threat worsens / Nation now seen as able to put nuclear warheads on missiles

David S. Cloud, David E. Sanger, New York Times

Published 4:00 am, Friday, April 29, 2005

2005-04-29 04:00:00 PDT Washington -- The head of the Defense Intelligence Agency said Thursday that U.S. intelligence agencies believe North Korea has mastered the technology for arming its missiles with nuclear warheads, an assessment that, if correct, means the North could build weapons to threaten Japan and perhaps the western United States.

While Vice Adm. Lowell Jacoby, the Defense Intelligence Agency chief, said in Senate testimony that North Korea is judged to have the capability to put a nuclear weapon atop its missiles, he stopped well short of saying it has already done so, or even that it has assembled warheads small enough for the purpose. Nor did he give any evidence to support his view during the public session of the Senate Armed Services Committee.

Still, his assessment of North Korea's progress exceeded what officials have publicly declared before.

When asked by Sen. Hillary Clinton, D-N.Y., during a hearing Thursday whether "North Korea has the ability to arm a missile with a nuclear device," Jacoby responded, "The assessment is that they have the capability to do that, yes, ma'am."

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At a White House new conference Thursday, President Bush said that given the uncertainties, he is worried about the progress North Korea has made on its nuclear program under its leader, Kim Jong Il. "There is concern about his capacity to deliver," he said. "We don't know if he can or not, but I think it's best when dealing with a tyrant like Kim Jong Il to assume that he can."

In 2003, the United States warned South Korea and Japan that satellite imagery had identified an advanced nuclear testing site in a remote corner of North Korea, where equipment had been set up to test conventional explosives that could compress a plutonium core and set off a compact nuclear explosion.

Since then, U.S. investigators have been pressing Pakistan for details about the kind of technology North Korean engineers might have been given, perhaps in conjunction with visits they made to Pakistani nuclear sites. North Korea supplied Pakistan with many of the missiles Pakistan uses for its own nuclear arsenal.

Building a nuclear warhead that can be delivered by a missile requires the technical sophistication to make it small and light. Moreover, being sure that warheads would work would probably require a test explosion, which North Korea has never conducted.

To field a working nuclear missile, North Korea would also have to conduct new tests of its missiles themselves and of their payloads, including such complex components as heat shields for re-entry of the warhead. North Korea's last significant missile test, in 1998, overshot Japan and would not have been able to reach U.S. territory.

North Korea is one of the most opaque intelligence targets for U.S. analysts, and the absence of reliable human spies have made it all the more difficult to understand the progress of its program.

Jacoby said that North Korea's ability to deliver a nuclear warhead to the continental United States remains theoretical because its Taepo Dong 2 missile has not been flight tested. But he added that U.S. intelligence agencies judge that a two-stage Taepo Dong could strike parts of the West Coast and that a three-stage variant could probably reach all of North America.

Thursday afternoon, Clinton called Jacoby's statement "the first confirmation, publicly, by the administration that the North Koreans have the ability to arm a missile with a nuclear device that can reach the United States. Put simply, they couldn't do that when George Bush became president, and now they can."

At his news conference, Bush defended his decision to pursue six-country diplomatic talks in an effort to stop North Korea's nuclear program, and noted that the United States is exploring various options, including taking the issue to the U.N. Security Council, if North Korea does not return to the talks.

"It's better to have more than one voice sending the same message to Kim Jong Il. It's the best way to deal with this issue diplomatically," he said. "We'll continue to do so."

A Defense Intelligence Agency spokesman, Donald Black, said Jacoby was reiterating testimony he gave last month before the committee, in which he said that North Korea's Taepo Dong 2 intercontinental ballistic missile "may be ready for testing. This missile could deliver a nuclear warhead to parts of the United States."

He did not say then that the North Koreans were capable of making a warhead that the missile could hurl such a distance.

Analysts with experience in Asia said the importance of Jacoby's conclusion is striking.

"This has to constrain the president's ability to deal with the North Korean nuclear problem," said Jonathan Pollack, a professor of Asian and Pacific Studies at the Naval War College who has written extensively on the North's program. "If you believe that Japanese territory is potentially at risk to a North Korean nuclear-armed missile, it has to change the calculation. "

If Bush accepts that judgment, it could significantly complicate choices he must make in the next several months. North Korea declared publicly for the first time in February that it has nuclear weapons. Earlier this month, U.S. spy satellites detected that the country had shut its nuclear power plant at Yongbyon and could be preparing to reprocess the plant's spent fuel, a move that could result in the production of enough plutonium to build two or three more nuclear bombs.

Jacoby said U.S. intelligence agencies have increased their assessment of the current North Korean arsenal's size, but he gave no numbers. Other government officials have estimated that North Korea's arsenal has increased by about six weapons' worth of plutonium since the North threw international inspectors out of the country in early 2003 and began turning a stockpile of 8, 000 spent fuel rods into plutonium.

Six-nation talks the United States is backing in an effort to persuade North Korea to abandon its nuclear program have been stalled since June. China, a neighbor and ally of communist North Korea, has hosted three inconclusive rounds of the negotiations, which involved the United States, North and South Korea, China, Japan and Russia.

John Pike, a defense analyst with GlobalSecurity.org, said U.S. estimates of the range of the Taepo Dong 2 and other North Korean missiles have nearly doubled in recent years. The increases, he said, may reflect U.S. intelligence agencies' improving understanding of the help North Korea has received from Pakistan, especially in designing warheads.

Smaller, lighter warheads could enable the North's missiles to fly farther, he said. "The range of the North Korean missiles keeps going up," he said. "I believe that's because of an evolving assessment of the extent to which they had access to Pakistani test data."